Re: [T3] FI doesn't want to run

[Jim Adney <jadney@vwtype3.org>]

On 1 Apr 2006 at 21:21, BOB2TYPE3S@aol.com wrote:

> jadney@vwtype3.org writes:
> 
> > With the key ON, depress the throttle slowly from the engine 
> > compartment. As the throttle opens you should hear a series of
> > clicks from the injectors.
> 
> OK, when I first tried this, I got no clicks. I hooked a spare one
> (thanks Russ), and now I get a series of clicks (I didn't count them,
> but there were many).Now I can actually see the spray pattern out of
> the injector while doing this (see below). I haven't refered to
> Bentley yet on setting these, as I've a 5 terminal switch that has 4
> wires running to it (it's made that way, remember it's a t-4 system).

Do you have a 5-wire plug with just 4 wires connected to it? 
Sometimes there is actually a 5th wire inside that was left 
disconnected for some markets. This can be connected for some 
applications....

>  >With the key ON and the coil disconnected, use a wrench to slowly
>  >turn the engine over. Listen for the point where the injectors
>  click, >which indicates that they are opening. You can also mimic
>  this by >taking out the dist and turning it by hand, thus triggering
>  the FI >trigger points.
> 
> At first I wasn't getting anything. Pulled the injectors out and
> watched them. Number 1 was just drizzling when off, and a steedy pee
> type stream when energized. Number 2, 3 and 4 didn't do anything.
> Pressure would drop off after shut down due to it leaking. Once
> replaced, the system would hold better pressure after it was shut off.
> Used a spare t-3 FI dizzy (after checking the points in the bottom)
> for a trigger device, and then slowy replaced the injectors (checking
> for good ones that would spray). This was an interesting learning
> experience, due to being able to hear the pump cycle whenever a pair
> of injectors was energized, and watch the spray pattern. : )  After I
> got to thinking about the 1st test for a while, I grabbed my spare t-4
> IAD and plugged that unit in (at the TPS), inplace of the one I had
> already installed. This brought a nice spray pattern out of the
> injectors as well. I'll change that in the morning when I go back to
> working on it again.

Using a second dist is a good way to do this. The TVSs sometimes wear 
out and give problems, but this won't change the spray pattern. It 
just changes whether you get a pulse or not. You can open up the TVS 
and look at the contacts, etc in there. It's actually quite 
complicated and I occasionally find one where someone has "fixed" it 
by breaking off some little gold wires, thus rendering it completely 
inoperable.

>  >If you don't hear the clicks, then there's some problem. It could be
>  >anything from a bad ground, bad wiring, bad brain, to rust frozen
>  >injectors.
> 
> Yup, frozen injectors is/was the culprit. 

Whenever I'm installing old injectors in an engine, I always push in 
on the pintle with the corner of a fingernail, just to verify that it 
can still move. They don't move far, but you can feel it if you're 
careful. It's also sometimes possible to free up one which is stuck. 
You can pull off the plastic cap to get better access to the tip of 
the pintle, but you need to be careful not to bend the pintle. With 
the plastic cap off, I've even tapped the tip agains a hard surface 
to break them loose. They will take a fairly hard blow as long and 
it's not at an angle.

Rust on the pintle or the seat MIGHT wear away once the engine gets 
some running time, but it might also cause a poor spray pattern that 
can't be improved. Rust in the seat area may keep them from ever 
sealing well again, too. I've not spent much time trying to recover 
bad injectors, but I HAVE had a few that were just sticky when I 
first tested them. Those seemed to recover nicely.  

The bigger problem is gas leaking out past the O-rings at the rear 
once those seals dry out. That, and rust, are the reasons I recommend 
that used injectors be stored in kerosene.  

Which injectors are you using? I have 1 or 2 NOS D-Jet 914 Bosch 
injectors here. I'd love to sell them now that my only 914 customers 
are long gone.  

-- 
*******************************
Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
*******************************

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